Tracing the Galactic Thick Disk to Solar Metallicities

We show that the Galactic thick disk reaches at least solar metallicities and that it experienced strong chemical enrichment during a period of ~3 Gyr, ending around 8-9 Gyr ago. This finding puts further constraints on the relation and interface between the thin and thick disks and their formation processes. Our results are based on a detailed elemental abundance analysis of 261 kinematically selected F and G dwarf stars in the solar neighborhood: 194 likely members of the thick disk and 67 likely members of the thin disk, in the range -1.3<~[Fe/H]<~+0.4. Based on data collected with the 6.5 m Magellan telescopes at the Las Campanas Observatory and with the Very Large Telescope at the European Southern Observatory (ESO proposal 72.B-0179). (Less)